Overview

Securing water for daily living is an important issue for any city. However, if rain doesn't fall or drought continues for a long time, there will inevitably be a water shortage. However, the current situation is that many buildings use the precious drinking and cooking water in toilets, etc. Our building gray water system is a system that purifies waste water that has been used once and re-uses it in building toilets and as non-potable water.

In buildings, this much water is used per person per day.

Equipment summary

Gray water equipment summary

Large pieces of debris are removed with a screen

Adjustment tank provides uniform water quality and water volume

Biological treatment is done in an aeration tank

Film treatment

Color and odors are removed in an ozone reaction tank

Sterilization

Gray water quality

Gray water quality

Application

Water for flushing toilets

PH

5.8-8.6

Odor

There must not be any abnormal odors

Appearance

Must be transparent and have almost no color

E. coli

Must not be detected

Free residual chlorine

0.1 mg/L or more

BOD

20 mg/L or less

COD

30 mg/L or less

From the Waste Water & Rain Water Reuse System Plan Criteria and descriptions (2004 version)

System & device summary

(1) Use a screen to remove large debris ( (2) Homogenize water amount and water quality in adjustment tank ( Do biological treatment in aeration tank ( (3) Use the rotating flat membrane separator AQUA UFO to do membrane treatment ( (4) Remove colors and odors in the ozone reaction tower ( (5) Sterilize.

Aeration tank

Ozone generator

Deodorizing device

*

AQUA UFO is a registered trademark of Hitachi Plant Technologies in Japan.

FAQ about gray water

Q. What can it be used for?
A. It can be re-used as toilet flushing water.

Q. What about holidays?
A. On holidays there is less waste water, but this system operates intermittently, operating and stopping according to the amount of waste water, so it is a streamlined treatment method. Operation can be restarted easily after a holiday is over.

Q. How is the removed debris processed?
A. It is separately incinerated and disposed of as industrial waste.

Q. Is there an odor or color?
A. We treat the water using ozone reaction devices and other devices, so there isn't enough color or odor to be a problem.

Q. How much tap water can be saved?
A. You can expect to save 30-50%. (Our test results)